Itou-san, who's poor at interpersonal relations, was jealous of her mild-mannered classmate Takahashi-san, who gets along well with everyone. But one day, she witnesses Takahashi-san swallow a person whole. Takahashi-san was a monster mimicking a human! Such a terrifying monster was calmly blending in with the class – that's extremely admirable!! I definitely want to be her friend!! And so Itou-san learns the "normality" of human society from Takahashi-san the monster. But while Itou-san is in high spirits, Takahashi-san has her own motives...